Drill mechanism



July 5, 1938. R. KJEFFREY DRILL MECHANISM 5 Sheets-Sheet 1 OriginalFiled Sept. 24, 1930 nos INVENTOR Robe/"7 xi-Jeffrey.

' July 5, 1938.

R; K. JEFFREY DRILL MECHANISM 3 Sheets-Sheet 2 Original Filed Sept. 24,1930 /NVEAITOF? Robe/f7 ff Jeffrey.

July 5, 1938. R. K. JEFFREY mum; macmmsu Original Filed Sept. 24, 1950 3Sheets-Sheet 3 Robe/f fl. Jeffrey.

Reissued July 5, 1938 UNITED STATES PATENT- OFFICE DRILL MECHANISMRobert K. Jeffrey, Columbus, Ohio, assignor to The Jeflrey ManufacturingCompany, Columbus,- Ohio, a corporation of Ohio 26 Claims.

The inventionrelates to improvements in drills of' the classwhereinmeansare provided for projecting and retracting an auger; whilethe same is-rotiated, relative to the drill frame, such drills beingcommonly used where itis desired to bore in a vertical face, such as acoal face, to provide shot holes 'forthe reception of the blastingcharges.

According to the present inventionmeans are provided to retract orWithdraw the auger with out reversing its direction of rotation.- Tothis end-the prime elements of the new mechanism area-rotating-longitudinally displaceable screw shaft to whichtheauger isattachable, a feed nut rotatable in the same-direction as the screwshaft, but at greaterspeed, so as to feed the shaft, clutch means toconnect the nut with'a rotary drive element, and meanstoarrest rotationofthe nut tow-ithdraw the shaft. The'clutch is provided with anon-rotating shipper member which, when movedinone-direction, engagesthe clutch elements, and, when moved in the opposite direction, comesinto frictional contact with a. braking'surface'associated with the'nutso asto arrest rotation of the-nut. Actuating-means are provided for theshipper member for moving the latter to the desired positionand'retaining it in such position and the clutch loading movement isyieldingly effected;

In addition to the more general features just mentioned, the inventionincludes subsidiary featuresas will hereinafter appear.

An illustrative embodiment of theinvention is shown in the accompanyingdrawings, in which Figure 1' is a side elevation of the completedrilling mechanism, with the floor engaging means shifted90 out ofnormal position in order to' show the detailed construction thereof.

Figure 2 is a plan view of the device shown in Figure-1.

Figure 315 a longitudinal section taken along the line 3'-3 of Figurefi.

Figure 4 is a=sectional view taken along the line H ofFi'gure '3 Figure5 is: a sectional view: taken along the line 5-5 of' Figure 3;

Figure 6 is a sectional view taken along the line 6-3 .01. Figure: 2;

Figure 7- is a: vertical section of the lower end oi the 'post showingone'means of adjusting the height thereofz' Figure 8-is*a section taken'along the line 8-8 of Figure 3', and is illustrative of one form ofanger mounting means.

Figure 9=is a sectional view-of a modified form of auger mounting-means;

Figure lO isa section taken-on the line |l0 of Figure '9'.

Figure "1 i'is a-diagrammatic view of the drilling mechanismset up foroperation.

(crass-47) Referring specifically to the drawings, in which like numbersindicate like parts, and particularly to Figure 11, there is provided apost 81 having a roof engaging member I 06 and an adjustable floorengaging member III. A drill supporting member 85 adapted to be slidablyfixed to said post by means of a bearing member 86 carries the motorcasing to which is attached, by bolts 26, the gear casing 25, whichcarries all of the gearing and clutch mechanism. The auger ordrilling'bit I is detachably held by a socket l6 fixed to theend of afeed screw H, which is operatively connected to a motor I8 within amotor casing which comprises a frame 20 having bearings 22 at one endthereof and a commutator housing 21 having bearings 23 at the other endthereof, the housing having fixed thereto a switch housing l9, as shownin Figure 3. An armature shaft 24 is mounted in the bearings Hand 23..

The casings Ill, 20, and 2|, thus formed and joined, make a unit whichis airtight in order to eliminate the danger of gas explosions, whilethe use of an electric motor is not essential, it is desirable;

Referring now more particularly to Figures 1, 2, and 3, ajournal bearing21 is cast integral with the top wall'of the field frame 20andisprovided with an elongated bushing 28 within which is rotatablymounted a driving quill 29 by means of which the feed screw I I issupported in the bearing 21. The said quill and feed screw are splinedtogether andthe latter derives driving power from the former. A gear 30keyed to the quill 29 meshes with a pinion 3T which is fixed to thearmature shaft 24 of the motor l8. Since the feed screw will extendrearwardly of the bearing 21, a pipe guard 32, screw threaded to saidbearing, is provided to prevent injury to the operator.

A sleeve 33 is positioned immediately in advance of the quill 29,partially within the gear casing 25, and partially within. a nut casing40,.

the latter being disposed in front of the former and fixed to thesleeve. The sleeve 33 surrounds the feed screw I! and its bore isslightly, larger than the diameter of said feed screw; in order that itmay be rotatably supported, ball bearings 35' are provided at one endthereof between the outside of the quill 29 and laterally extendingannular flange 36, and at the other end thereof by ball bearings 31fitted into the bore of a bearing 38 of the gear casing 25. A cap orgudgeon. 39 closes the end of the bearing 38 and'holds the bearings 3'!in proper place. The sleeve 33 is the means for driving or holding a nut34 depending on'thedirection of feed desired, which operation willbelater described. A friction plate or flange 4| is cast integral with oneend of the sleeve 33' and a second friction plate or flange 42 is keyedto the sleeve and longitudinally spaced fromplate 4|. Between saidfriction plates the sleeve 33 is provided with a bushing 43upon which isrotatably and slidably mounted the hub 44 of a gear 45 which meshes witha pinion 46 fixed to the outer end of the armature shaft 24.

A shipper ring or collar 41 provided with a flange 48 having a clutchlining 49 fixed to its outer face encircles the elongated hub 44 of thegear 45. The shipper ring is provided with thrust members positioned ateither side of a radial flange formed at the free end of hub 44, therebeing a plain thrust ring at the left of the flange and a ball bearingassembly at the right thereof, Fig. 3.

Thus the gear 45 may be shifted to the left through the shipper memberwith a minimum of friction, elimination of friction in moving the gearto the.right being unessential, as will appear. The gear 45 is providedwith a plate center 59 to the outer face of which is fixed a clutchlining 5I. A lever in the form of a yoke, 52 is pivoted at its upper endto the gear casing 25 on a pin 53, and is connected to the shiftercollar 41 by pins or trunnions 54, being adapted to be swunglongitudinally of the sleeve 33 in one direction in order to operativelyconnect the gear 45 to the said sleeve through plate 4| and therebyrotate the nut casing 49, or when shifted in the opposite direction toengage the clutch shifter collar 41 with flange 42 and thereby arrestrotation of sleeve 33 and nut casing 49, the collar being held againstrotation by pins 54.

The nut 34, as shown in Figures 3 and 5, is made in two parts, each partbeing provided at one end thereof with a pair of ears 55 pierced bysuitably aligned apertures. The nut casing 49 comprises a cylindricalouter wall 55 and is provided with inwardly extending flanges 51 and 58which form a pocket 59. The said flanges are pierced by diametricallydisposed aligned apertures adapted to receive pins 69 and 5| which arefixed to the nut casing 49 against longitudinal movement by shoulders 62and cotter pins 63.

The pins 69 and 6! extend through apertures: in the ears 55 of each halfof the nut. The cars 55 being positioned between flanges 51 and 58,longitudinal movement of the nut relative to the -nut casing isprevented, and rotary movement of each half of the nut about the pins 99and BI is permitted. Encircling the two halves of the nut in order tohold them in engagement with the feed screw is a feed nut sleeve 65which is provided at its outer end with a spring pressed detent 66 ofusual construction, adapted to fit a groove 61 cut in the periphery ofthe nut. This arrangement prevents longitudinal movement of the sleeverelative to the nut except when it is desired to remove the sleeve inorder that the nut may be disengage-d from the feed screw. Springs 69are Wound around the pins 59 and 6! and the ends 69 abut against theouter wall of the pocket 59, while the ends I9 extend between the nuthalves. The springs are so arranged that they exert an outwardlydirected force against each part of the nut and the tendency is to moveeach half about its pivot to in.- operative position to cause thedisengagement "from the feed screw.

'to maintain. them in properly spaced relationship.

Similar bosses I2 are provided at their lowermost portions and by meansof a bolt I3 the two members are clamped together. Depending downwardlyfrom the bosses I2 are lugs I4. each' provided with an aperture in whichis journaled a trunnion pin I5 of a nut IE. A- screwthreaded shaft 11provided with a'ha-nd wheel 89 extends through a bearing I9 of the gearcasing and into the nut 76. A spring cup 8| abuts a shoulder 82 of theshaft TI and is held thereagainst by a spring 83 interposed between saidcup and gear case, thereby preventing longitudinally non-rotativedisplacement of the shaft I1 relative to the gear case except undercertain conditions later to be described.

An arcuate flange 84, the periphery of which extends 180, is castintegral with the motor casing 29. A drill supporting member 85 having abearing 86 adapted to be fixed to the post 81 is also provided withanarcuate flange 88, the

periphery of which extends through 180. It will.

be noted in Figure 6-that the flanges 84 and- 89, when in assembledrelation, lock with each other, and thereby support the drill mechanismon the post. I In order that the parts may be held in fixed relation,there is: provided a screw shaft 89, concentric with the arcuateflanges, extending through a bearing sleeve 99 of member 85 into a screwthreaded aperture of a boss 9| formed on the motor casing 29. On theouter end of the shaft 89 is a hand wheel 92 which when rotated inwardlysecurely clamps the casting B5 to the motor casing, and when rotatedoutwardly until the shaft 89 is entirely clear of the boss 9|, allowsthe parts to be disassembled.

The drill mechanism'is adjustable on the pos 81 without disassemblingthe parts. The-bear? ing 85 which carries the flange 88 is providedwitha pair of apertured lugs 93 through which 1 extends a pin .94. .A lever95 having a pawl.

nose 96 is pivoted on the pin Y94 and the nosev 96 is engageable withthe teeth 91 on said post. A spring 98 is interposed between the boss 99of the bearing 85 and an offset I99 of the lever 95, and tends to keepthe nose 96 engaged with the teeth 91. A boss I9I isprovided onthebearing 85, and a clamping bolt I92 having a.

handle I93 prevents vertical movement of the bearing on the post.

In order that the entire post and drill will be in balanced relation,the floor and roof engaging means are offset as indicated with referenceto the floor engaging means. in Figure 1. The roof engaging meanscomprises an "arm I394 clamped to the post by the bolt I95 and isprovided with a pointed member I96. The floor engaging means isadjustable to different heights and comprises an arm I M clamped to thepost by a bolt I98 and provided with a bearing member I99 inside ofwhich is slidably mounted a jack pipe I I9. As shown in Figure '7, thebearing member I99 is provided with a pair of apertured lugsas at- I49through which extends the pin I45. A lever I42 having a pawl nose I43 ispiV-' oted on the pin I4I andthe nose I43 is engageable with teeth I44on said jack pipe. I45 is interposedbetween bearing member I99 and anoffset I46 of lever I42, and tends to keep the nose I43 engaged with theteeth I44. A boss M1 is provided on the bearing I99 and a clamping boltI49 having'a handle I49 prevents vertical movement of the bearing. onthe post. Further adjusting mechanism is provided by the screw jack IIImounted Within the jack pipe H9 and having a hand wheel H2 which is heldagainst the longitudinal movement away from the jack pipe by means of aspring-pressed pin II3 engaging a shoulder I I4 turned on the jack Aspring pipe. The-screw jack III is provided with a keyway extendingthroughout the length thereof and a key I-l5 formed in the bore of thejack. pipe IIO' prevents rotation of said screw jack when the hand wheelI I2 is rotated. Therefore, by rotation of saidhand wheel the screw jackwill be moved longitudinally of the jack pipe to adjust the overalllength of the post mounting.

One form of auger socket is shown in Figures 2, 3 and 8- and comprises asocket portion II 6 adapted to fit over the end of the feed screw I1 andrigidly fixed thereto by rivets Ill. The opposite end of the socket isprovided with a pocket of polygonal cross section andis adapted toreceive the tail piece H8 of the auger. When transporting the drill fromone place to another or in changing angers, it is necessary to removethe auger from its connection with the feed screw; In order that thismay be done the tail piece H8 of the auger is provided with atransversely extending groove H9 which when assembled with the socket isin partial register with a suitable aperture I29 in said socket, throughwhich extends a pin I2I, said pin being so positionedthat it will holdthe two parts in working relation. By rotation of the pin IZI, a flatportion I22 will be brought into register with the said tail piece ofthe auger to permit removal of the auger.

A second form of auger socket is shown in Figures 9 andlO. The tailpiece I I8 of the auger is-riveted in said socket which at its other endis-provided with internal keys I23 cast integral therewith-and engagedin key-ways of screw IT to prevent rotation of the feed screw andsocket. A ring I24 is positioned around the outer periphcry. of saidsocket and is provided with a pin I25 adapted to be inserted through anaperture I26 in the socket wall and into a radial recess I2'I in thefeed screw. The said ring is sufliciently largeto permit removal of pinI25 from said recessz-so that the socket may be disengaged from the endof the feed screw. A spring I28 is seated in a notch 29 in the socketand has laterally extending arms I30 which engage the inner surface ofthe ring to hold the ring I24 in the position shown to preventaccidental disengagement of pin I25 from the recess I21, but allowingremoval of said pin from said recess upon forced flexure of the spring.Lugs I3! are cast integral with. the socket to prevent lon itudinalmovement of the ring I24 relative to the socket. The use of this form ofsocket permits removal of the. feed screw from its association with theotherv parts. To accomplish this, the socket is removed from the end ofthe feed screw and the sleeve 65 is removed fromv the nut 34 wherebyeachihalf of said nut is rotated by its associated spring about itspivotal connection with the nut casing 40 to disengage the threads ofthe nut fromthe feed screw which may then be pulled out the rear end ofthe guard pipe 32.

The drill mechanism is thus removably attached to the post andvertically adjustable thereon. It may be adjusted about a horizontalpivot or the entire post and drill may be adjusted about the floor androof engaging means in order to place the drill in position for thedrilling of holes in various angles to the coal face.

When it is desired to take down or set up the parts of the drill inworking relation, the post is inverted toplace the floor engaging meansat the top in such a position that the flange 88 is in line with thegroove of the motor casing flange 88 so that said flange is engaged in agroove formed by theflange 84. When the post is in an upright positionwith the connection made as described, the parts are in assembledrelation.

In operation, after the post is properly set up with relation to thecoal face, the drill mechanism may be raised by lifting thedrillmechanism and in so doing allowing the pawl nose 95 to slide overthe teeth 97, and the drill mechanism may be lowered by lifting thelever 95 to disengage the pawl nose 96 from the teeth 81. The clampingscrew I92 may be tightened to securely hold the drill in properlyadjusted position on the post.

By means of the novel arrangement of parts, the feed screw rotates theauger at the desired cutting speed and it may be fed in eitherdirection, forwardly a relatively slow feeding speed and reversely at arelatively high withdrawal speed. It will be noted that when the gear.45 is shifted to the left by means of the shifter collar 41, referringto Figure 3, a contact is made between the plate center 50 on the gearand the flange 4!, the spring 83 acts as an abutment and should thecutting become too hard for feeding at the usual feed of fifty inchesper minute, the spring will be compressed which allows slipping of theclutch. When the shifter collar is moved in the opposite direction theclutch 49 Will-be engaged to prevent rotation of the nut, and since thefeed screw is rotated clock-wise and the threads are left handed, thefeed screw will be moved in a reverse direction. When this operation isperformed the hand wheel abuts the boss I9. A spring could be interposedbetween the boss 79 and the hand wheel 89, but it has been foundunnecessary to satisfactory operation since the feed screw will not beoverloaded when withdrawing the auger.

The plate 56 with its lining or face 5! constitutes one element of afriction clutch the other element of which is the friction plate II. Ina similar manner the plate 48'andlining or face 49 constitute oneelement of the other friction clutch, the other element of which is thefriction plate 42." When the manually operable mechanism comprising thewheel 80 and the screw-threaded rod I8 holds the clutch elements d8, t9and 5t, 5! midway between the clutch elements 4! and 42 out of contactwith both, the drill will be retained in-neutral position so far as feedis concerned, although it may continue to rotate to cause theconvolutions of the drill as shown at in Figure 11, to convey thecuttings rearwarclly out of the previously drilled hole.

It will thus be seen that the threaded bar I"! may be continuallyrotated in the same direction and while being so rotated the drill maybe fed forwardly, the forward feed may be stopped to finish the bottomof the drill hole and to remove some of the cuttings from the hole, andthen fed backward to remove the drill from the hole while cleaning outremaining cuttings from the hole While the drill is rotating in the samedirection as it rotated during the drilling operation.

The mining drill therefore includes a housing 25 in which is operativelyarranged a threaded tool for longitudinal movement in one directionthrough the housing and for retractible movement in the oppositedirection through the housing, and driving means connected through atrain of gearing to the tool to impart rotative and reciprocal movementsto the tool. Such train when the post is rotated about the center ofthe,

of gearing includes clutch means controlled by a manually movable member52 movable into selective positions whereby the clutch means may bealternatively actuated to effect feeding movement of the tool when themember 52 is in its left-hand position as viewed in Fig. 3, to retainthe tool neutral and rotative when the member '52 is in its centralposition, and to effect retraction of the tool when the member 52 is inits right-hand position.

When the motor I8 is operating, the drilling tool is being driven in aclockwise direction as viewed from its rear end. When the lever 52 ismoved to the left as viewed in Fig. 3 the nut 34 will also be rotated ina clockwise direction but at a higher speed as determined by the gearratios at 3|, 30 and 4B, 45, the pinion being of greater diameter thanthe diameter of the pinion 3|, and the diameter of the gear 45 beingless than the diameter of the gear 3!], as shown in Fig. 3. Thedifferential between the clockwise rotation of the left-hand threads I1and the clockwise rotation of the nut 34 will result in a slow forwardfeeding movement of the drilling tool.

When the lever 52 is in central or neutral position the nut 34 is freeto rotate with the screwthreaded rod l1 and consequently the drill willcontinue to rotate in a clockwise direction without being fed orretracted. When the lever 52 is moved to its right-hand position the nut34 Will be held stationary by the engagement of the clutch elements 48,49, and 42, the gear being free to rotate relatively to the element 48by rea son of the ball thrust bearing shown in Fig. 3.

:When the nut 34 is thus held against rotation the clockwise rotation ofthe left-handed threads ll will effect a relatively quick retraction ofthe drill from the hole while cleaning it of cuttings therein.

The ratio of reduction between pinion 3| and gear 30 is greater thanthat between pinion 46 and gear 45. In fact, the motor revolving at 3000R. P. M. will rotate the gear 30 at 600 R. P. M. and the gear 45 at 800R. P. M. Since the differ- ..-ence in R. P. M. is 200 and the lefthanded per minute.

threads on the feed screw are four per inch, the auger will be fed intothe coal at the rate of fifty inches per minute. The reverse feed willbe three times at fast, or one hundred and fifty inches Experimentationis actual use has proven the above described drill mechanism to beexceedingly efficient, the new mechanisms overcoming many of theobjectionable deficiencies in the electric drills in use heretofore.

The tool holder herein described has been covered in a divisionalapplication" Serial No. 599,965, filed March 19, 1932, now Patent No.1,954,049 granted April 10, 1934. The feed nut is covered in adivisional application Serial No. 19,092, filed April 30, 1935, nowPatent No. 2,030,637 granted February 11, 1936.

It is understood that there are various forms and modifications of thedrill mechanism shown in the present disclosure which are within thespirit and scope of the appended claims.

I claim:

1. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, means to rotate the nut in the same direction as the shaftand at a speed greater than that of the shaft to cause longitudinaldisplacement of the latter in one direction, and friction brake meansfor arresting rotation of the nut during rotation of the shaft to causedisplacement of the shaft in the other direction.

2. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, means including a friction clutch to rotate the nut in thesame direction as the shaft and at a speed greater than that of theshaft to cause longitudinal displacement of the latter in one direction,brake means for arresting the rotation of the nut during rotation of theshaft to cause displacement of the shaft in the other direction,and'means to control said clutch, said last named means being operableto engage the clutch and hold it in engaged disposition.

3. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, means including a friction clutch to rotate the nut in thesame direction as the shaft and at a speed greater than that of theshaft to cause longitudinal displacement of the latter in one direction,brake means for arresting the rotation of the nut during rotation of theshaft to cause displacement of the shaft in the other direction, andmeans to control said clutch, said last named means being operable toengage the clutch and hold it yieldingly in engaged disposition.

4. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, a gear mounted concentrically with said shaft and rotatableindependently thereof, cooperating friction clutch elements between thegear and nut whereby the former is adapted to drive the latter, meansfor engaging said clutch elements, means to rotate the gear and therebythe nut in the same direction as the shaft and at a speed greater thanthat of the shaft to displace the latter longitudinally in onedirection, and friction brake means for arresting rotation of the nutduring rotation of the shaft to cause displacement of the shaft in theother direction.

5. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, a rotatable sleeve freely surrounding the shaft and securedto the nut, a gear mounted concentrically with the shaft, a frictionclutch comprising driving and driven elements in connection with thegear and sleeve respectively, means to rotate the gear in the samedirection as the shaft and at a speed greater than that of the shaft,meansoperable to engage the clutch elements and hold them in engagedrelation to cause rotation of the nut at the speed of the gear andthereby effect longitudinal displacement of the shaft in one direction,and friction brake means for arresting rotation of the nut when theclutch elements are disengaged whereby continued rotation of the shafteffects displacement of the shaft in the other direction.

6. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut engaging the threads ofsaid shaft, a rotatable sleeve freely surrounding the shaft and securedto the nut, a gear mounted concentrically with said sleeve, opposedfriction surfaces on the gear and sleeve, means for axially displacingthe gear to engage and disengage said surfaces, means to rotate the gearin the same direction as the shaft and at a speed greater than that ofthe shaft, the nut being rotated at the speed of the gear uponengagement of the friction surfaces to displace :the shaft in onedirection, and brake meansfor: arresting rotation of the nut when the.friction surfaces are disengaged whereby continued rotation of theshaft eflects displacement of the shaft in the other direction.

7. In apparatus of the classdescribeda longitudinally displaceable screwshaft, means to rotate said shaft,.a rotatable sleeve freelysurrounding. said shaft, a nut fixed to saidsleeve and engaging thethreads of said shaft, a pair of spaced. radialiflanges on said sleeve,a gear rotatably mounted on said sleeve between said flanges,anon-rotating shipper member mounted in connection with the gear toshift the latter axially, said .gearhaving a friction surface adapted toengage one of the flanges to drive the sleeve and nut when the gear isshifted in one direction, said shipper memberlhaving a frictionsurfaceadaptedto engage the other of said flanges when the gear is shifted inthe other direction, and means to drive said gear in the same directionas the shaft and at a speed greater than that of the shaft.

8. .In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate saidshaft, a rotatable sleeve freelysurrounding said shaft, a nut fixed to said sleeve and engaging thethreads of said shaft, a pair of spaced radial flanges on said sleeve, agear having an elongated hub rotatably mounted on said sleeve betweensaid flanges, a non-rotating shipper'ring in connection with said hub toshift the gear axially, said gear having a friction surface adapted toengage one of the flanges to drive the sleeve and nut when the gear isshifted in one direction, said shipper ring having a friction surfaceadapted to engage the other of said flanges when the gear is shifted inthe other direction, and means to drive said gear in the same directionas the shaft and at a speed greater than that of the shaft.

9. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a rotatable sleeve freelysurrounding said shaft, a nut fixed to said sleeve and engaging thethreads of said shaft, a pair of spaced radial flanges on said sleeve, agear having an elongated hub rotatably mounted on said sleeve betweensaid flanges, said hub having a radially projecting portion spaced fromthe gear, a non-rotating shipper ring having an internal circumferentialgroove in which the radially projecting portion of the hub is engaged,said gear having a friction surface adapted to engage one of the flangesto drive the sleeve and nut when the gear is shifted in one direction,said shipper ring having a friction surface adapted to engage the otherof said flanges when the gear is shifted in the other direction, andmeans to drive said gear in the same direction as the shaft and at aspeed greater than that of the shaft.

10. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a rotatable sleeve freelysurrounding said shaft, a nut fixed to said sleeve and engaging thethreads of said shaft, a pair of spaced radial flanges on said sleeve, agear having an elongated hub rotatably mounted on said sleeve betweensaid flanges, said hub having a radially projecting portion spaced fromthe gear, a. shipper ringhaving an internal circumferential groove inwhich the radially projecting portion of the hub is engaged, said gearhaving a friction surface adapted to engage one of the flanges to drivethe sleeve and nut when the gear is shifted in one direction, saidshipper ring having a friction surface adapted to engage the other ofsaid flanges when the gear is shifted in the other direction, a shiftinglever pivoted to said shipper ring and restraining the latter againstrotation, and means to drive said gear in the same direction as theshaft and at a speed greater than that of the shaft.

11. In an apparatus of the class described, a longitudinallydisplaceable screw shaft, means to rotate said shaft, a rotatable sleevetfreely surrounding said shaft, a nut fixedto said sleeve and engagingthe threads of said shaft, a pair of spaced radial flanges on saidsleeve, a gear having an elongated hub rotatablymounted on said sleevebetween said flanges, said hub having a radially projecting portionspacedfrom .the gear, a non-rotating shipper ring having an internalcircumferential groove in which the radially projecting portion of thehub is engaged, said gear having a friction surface adapted to-engageone of the flanges to drive the sleeve and nut when the gear is shiftedin one direction, said shipper ring having a friction surface adapted toengage the other of said flanges when the gear is shifted in the otherdirection, a shifting lever pivoted to said shipper ring and restrainingthe latter against rotation, a self-locking screw and nut unit forswinging said lever, and means to drive said gear in the same directionasthe shaft and at a speed greater than that of the shaft.

12. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotate said shaft, a nut on said shaft, a rotaryelement on said shaft, means to drive said rotary element in the samedirection as the shaft and at a speed greater than that of the shaft,clutch means between said rotary element and said-nut, and operatingmechanism for said clutch means comprising a self-locking screw and nutunit.

13. In apparatus of the class described, alongitudinally displaceablescrew shaft, means to rotate said shaft, a nut on said shaft, a rotaryelement on said shaft, meansto drive said rotary element in the samedirection as the shaft and at a speed greater than that of the shaft,clutch means between said rotary element and said nut, and operatingmechanism for said clutch means comprising a self-locking screw and nutunit and a spring receiving the .reaction of said unit.

14. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to rotatesaid shaft, a nut on said shaft, a sleevefreely rotatable on said shaft and fixed to said nut, a rotary elementon said sleeve, a friction clutch comprising cooperating partsinconnection with said nut and rotary element respectively, means toshift said rotary element to engage said parts, and means to drive therotary element in the same direction as the shaft and at a speed greaterthan that of the shaft.

15. In apparatus of the class described, a longitudinally displaceablescrew shaft, a gear splined on said shaft, a nut engaging the threads ofsaid shaft, a sleeve freely rotatable on said shaft and fixed to saidnut, a gear rotatable on said sleeve, a drive shaft, pinions on saiddrive shaft respectively engaging the gears todrive the same,cooperating clutch elements on said rotatable gear and sleeve, and meansfor axially displacing said revoluble gear to engage said'clutchelements and drive the nut, the drive-ratio to said nut being greaterthan that to said shaft.

16. In apparatus of the class described, a 10ngitudinally displaceablescrew shaft, a gear splined on said shaft, a nut engaging the threads ofsaid shaft, a gear freely rotatable on the axis of said shaft, frictionclutch means operable to connect the last named gear and nut, brakemeans operable to hold said nut against rotation upon disengagement ofsaid friction clutch means, a power shaft, and pinions on said powershaft respectively engaging the gears to drive the same, the drive ratioto said nut being greater than that to said shaft.

17. In apparatus of the class described, drill mechanism and housingmeans therefor, said mechanism comprising a rotatable screw shaftextending through said housing and longitudinally displaceable relativethereto, a gear splined on said shaft, a nut engaging the threads ofsaid shaft, a gear freely rotatable on the axis of said shaft, frictionclutch means operable to connect said last named gear and nut, a motorcasing in connection with said housing means, an electric motor in saidcasing with its armature shaft parallel to said screw shaft, and pinionson said armature shaft respectively engaging the gears to drive thesame, the drive ratio to said nut being greater than that to said shaft.

18.'In apparatus of the class described, drill mechanism and housingmeans therefor, said mechanism comprising a rotatable screw shaftextending through said housing and longitudinally displaceable relativethereto, a gear splined on said shaft, a nut engaging the threads ofsaid shaft, 2. gear freely rotatable on the axis of said shaft, frictionclutch means operable to connect said last named gear and nut, brakemeans operable to hold said nut against rotation upon disengagement ofsaid friction clutch means, a motor casing in connection with saidhousing means, an electric motor in said casing with its armature shaftparallel to said screw shaft, and pinions on said armature shaftrespectively engaging the gears to drive the same, the drive ratio tosaid nut being greater than that to said shaft.

19. In a mining drill, the combination of a housing, a threaded tooloperatively arranged in said housing for longitudinal movement in onedirection through the housing and for retractible movement in theopposite direction through said housing, a driving means, a train ofgearing including friction clutch means adapted to be actuated by saiddriving means for imparting rotative and reciprocal movement to saidtool, a controllable means for such clutch means, said controllablemeans including a manually movable member, movable into selectivepositions whereby the clutch may be alternatively actuated to impartreciprocal movement to said tool when such member is in one position, inanother position to retain the tool neutral and rotative and in anotherposition to impart to the tool reciprocal movement in the oppositedirection.

20. In apparatus of the class described, the combination with alongitudinally movable screw shaft, of means to rotate said shaft, arotatably mounted feed nut constructed and arranged to be in engagementwith said shaft to cause feeding longitudinal movement thereof upon theoccurrence of relative rotary movement between the two and. to bereleased to permit free longitudinal movement of said shaft, means torotate said feed nut in the same direction and at a greater speed thanthat of said shaft to cause longitudinal feeding movement of said shaftin one direction, and means to rotate said shaft at a greater speed thansaid feed nut to cause longitudinal feeding movement of said shaft inthe other direction. 1

21. In apparatus of the class described, a longitudinally displaceablescrew shaft, means to r0- tate said shaft, a sectional feed nut soconstructed and arranged that in one relation of parts the threadsthereof engage the screw shaft threads and in another relation do notengage the screw shaft threads, means to rotate the nut in the samedirection as the shaft and at a speed greater than that of the shaft tocause longitudinal displacement of the latter in one direction, andmeans for arresting rotation of the nut during rotation of the shaft tocause displacement of the shaft in the other direction.

22. In a drill, the combination with a gear casing, of a feed screwextending through said casing, drive means for rotating said screw whileproviding for longitudinal movement thereof, a feed nut located outsidesaid .gear casing and threaded on said screw, a drive tube for drivingsaid feed nut and extending from within said gear casing to a positionoutside said gear casing, said tube surrounding said feedscrew, andmeans for rotating said tube and consequently rotating said feed nut tofeed said screw longitudinally.

23. In a drill, the combination with a gear casing, of a feed screwextending through said casing, means for rotating said screw whileproviding for longitudinal movement thereof, a feed nut threaded on saidscrew and located outside said'gear casing, means for rotating said feednut at a greater speed than that of the screw and in the same direction,said means including a tube surrounding said screw and extending throughsaid gear casing.

24, In a drill, the combination with a longitudinally movable screwshaft, of means for rotating said shaft and providing for longitudinalmovement thereof, a sectional feed nut threaded on said shaft andreleasable to permit free longitudinal movement thereof, and means torotate said feed nut in the same direction as that of the shaft and at agreater speed, said means including a tubular drive member connected atone end to said nut, said member surrounding said shaft and constructedto permit free longitudinal and rotary movement of said shaft withrespect thereto.

25. In a drill, the combination with a longi-- tudinally movable screwshaft, of means for rotating said shaft and providing for longitudinalmovement thereof, a sectional feed nut threaded on said shaft andreleasable to permit free longitudinal movement thereof, and means torotate said feed nut, said means including a tubular drive memberconnected at one end to said nut, said member surrounding said shaft andconstructed to permit free longitudinal and rotary movement of saidshaft with respect thereto.

26. In a drill, the combination with a longitudinally movable screwshaft, of means for rotating said shaft, a feed nut threaded on saidshaft, and means for driving said feed nut in the same direction as thatof said shaft and at a greater speed including a rotary tubular membersurrounding said shaft and providing for free rotation and longitudinalmovement of said shaft therethrough.

ROBERT K. JEFFREY.

